


The Burning Brotherhood - A Shadowhunters fanfiction

by Silvandar



Category: Shadowhunters (TV)
Genre: Downworlders, Explicit Language, Explicit Sexual Content, F/M, M/M, Malec, Sexual Content, Shadow World, Shadowhunters - Freeform, after events of The Mortal Instruments, clace
Language: English
Status: In-Progress
Published: 2016-02-29
Updated: 2017-10-04
Packaged: 2018-05-23 22:33:58
Rating: Explicit
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 3
Words: 3,425
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/6132347
Author URL: https://archiveofourown.org/users/Silvandar/pseuds/Silvandar
Summary: <blockquote class="userstuff">
              <p>After a long spell of world saving and rule breaking, Clary, Jace, Alec and Isabelle return to the New York Institute to allow Clary to complete her Shadowhunter training. As the Shadow world recovers from the horrors unleashed by Jonathon Morgenstern, there is hope that the new Clave and council will ensure peace for shadowhunters and downworlders alike. However, when the sinister Harbingers of Death begin murdering downworlders, it seems that once again the fragile peace is at risk.</p>
            </blockquote>





	1. Time of Peace

**Author's Note:**

> "Shadowhunters" and "The Mortal Instruments" are the property of Cassandra Clare. This fanfiction is not intended to profit in any way from that property. The Burning Brotherhood is intended as a tribute to the fascinating and beautifully detailed world of Shadowhunters.

"It's not opening."

 Alec grunted as Jace pushed him aside, the shorter blonde throwing his weight into the door. "Told you" he added, watching Jace wince and grip his shoulder.

 "Fine. Clary, can you do something with this?"

 "I'm not sure this is a good idea" Clary replied, looking worried. "I mean, I can see the rune to get past the wards, but..."

 "Clary" Alec stood in front of her and folded his arms, his expression pained. "I need this... I need you to do this for me."

 Clary sighed and gently moved Alec out of the way, crossing to the heavy oak cabinet and pulling out her stele. The rune floated in her mind, a sizzling blade cutting through the wards surrounding the dark wood. With a slightly guilty look, she drew the rune and then stepped back as the wards seemed to shatter like glass. A simple unlock rune followed, and Alec wrenched open the doors.

 "Woah" Jace muttered, "what even is all this stuff?"

 Alec, an interesting shade of crimson, ignored his question and pushed aside some exotic looking leather goods and some suggestively shaped wrapped bundles. Eventually, he seemed to find what he was looking for – a small box which he opened quickly, peered inside and then slammed shut.

 "Got it. Let's go."

 "He's going to notice the wards are broken" Clary objected as Alec re-locked the cabinet. "How are you going to explain it?"

 "I'm not planning to" the tall shadowhunter replied, "I'm hoping that by the time he realises, it'll be irrelevant."

 "Rather you than me" Jace muttered, then glanced down as Clary hid something in her bag. "Did you steal something out of there?"

 "Of course not" she said, pushing past them with a flush on her face. Alec chuckled softly and followed her out Magnus' bedroom. With a confused last look at the cabinet, Jace followed.

 

* * *

 

For three days, Alec had been worrying. Three days since Magnus had admitted that it was his birthday soon, and that he was refusing to say how old he was. Alec had been frantic over what present to get him, quite reasonably concluding that Magnus could already get absolutely anything he wanted for himself. The only thing Alec could come up with was something highly personal, and that Magnus would never see coming. Hence the raid on the warlock's bedroom "toy" cabinet.

Wondering, not for the first time, how Jace could be so ignorant of such things, he opened the box he had so carefully hidden from the blonde shadowhunters gaze. He definitely didn't want Jace seeing the contents – a beautifully crafted set of restraints and a male chastity belt which was reinforced with Magnus' magic.

The set had been a gift to Alec himself, who had immediately freaked out and refused to touch it. It had been an early attempt to get his lover into kink which Magnus had not repeated. Tossed into the back of the cupboard and forgotten, it was key to Alec's plans for his lover's birthday treat.

As he checked over the device to make sure it was clean and ready for use, he reflected on what he'd seen Clary steal. He considered that Jace was in for some interesting times when she decided to play with the soft leather manacles...

 

* * *

 

"I don't get it" Jace said, throwing himself down on Clary's bed. He was in training gear and had a rumpled look to him as he stretched out. "All of that fuss for what, a box of jewellry or something?"

Clary, who had caught a very fast glimpse into the box as Alec opened it, smirked a little as she changed her clothes behind the bathroom door. "Maybe you should ask him, if you're that curious?"

"No thanks, the less I know the better. Besides, what Alec choses to buy his boyfriend is none of my..." his voice choked off as Clary came back into the bedroom and he stared at her.

"None of your what?" she asked, then looked at him properly. "What is it?!" she asked, his sudden silence frightening her.

With difficulty, Jace tore his eyes away from the pale white silk dressing gown she was wearing over her nightdress. The hem came to her mid thigh, exposing a long, slim expanse of pale skin. Raising his eyes to her face didn't help – her vivid hair fell in soft curls over the gentle v of her outfit. One of the shoulders of her dressing gown had slipped, revealing even more pale flesh, marked with dark runes. She was unconciously beautiful and he suddenly realised he had no idea how to breathe.

"Jace!" she said, crossing to him and touching his shoulder. "What's wrong with you?!"

Her touch was like a shock and he leapt to his feet, making her stumble backwards. As his instincts kicked in to catch her he realised he was now holding her in his arms, cool silk under his fingers and her huge green eyes scanning his face in confusion and worry. Annoyed that his gawping had frightened her, he pulled her close to him and kissed her.

Clary melted under his touch, as always. As she met his kiss with her own, fire seemed to spark in her belly and leave her nerves tingling. She barely noticed that she was unzipping his sweatshirt and running her hands over his chest. It was only when he groaned into the kiss that she caught herself and reluctantly pulled away.

"Jace... we can't" she said, shaking her head sadly. "Not here..."

"Why not?" he asked, his voice almost plaintive. "We're adults, we're not breaking any rules..."

"What if someone walked in? What if..."

"Noone's going to walk into your room, Clary" he said, pulling her back into his arms. Feeling her resistance, he added "I could put a locking rune on the door if that would help?"

Clary bit her lip, thinking of how ashamed she would be if someone caught them, of how awkward it would be if anyone _heard_ them. An idea suddenly jumped into her mind, and she grabbed her stele. "Lock the door" she ordered, turning the point on her thigh and quickly carving the rune for silence.

Jace watched her for a second and then realised what she was thinking. In moments he had locked the door and carved a matching rune on himself, then wrapped his arms around her. Sitting on the bed, he pulled her into his lap and drew her into a deep kiss.

 

* * *

 

As the lights in the institute faded and New York crept into the uneasy twilight which served as its sleep, a dark figure perched on the roof opposite the shadowhunter base. Almost invisible in the shadows, a second figure stood watch at ground level. A glance between them was all the communication they seemed to need before they moved as one, running towards the institute and clearing the surrounding walls in a few bounds.

The first figure, the taller of the two, leaped directly onto the north tower of the old church. Its landing was silent and it scrambled to the higher levels, disappearing into a broken window pane. The second figure pressed itself against the walls as it skirted the building, making for the broken boundary which marked the back door. Pausing inside what was once the stairs to the crypt, the figure muttered a few words and then pulled open the door.

It took only seconds for the New York Institute to be breached.


	2. Theft and destruction

Maryse Lightwood stood at the center of the Institute, giving crisp orders. Her expression was fierce, her body stiff and angry. The shadowhunters scuttled around her, desperate to be out from under that gaze as they carried out their duties.

The New York Institute was in chaos. As Jace prowled through the room he heard snippets of gossip, rumors of what had happened. By the time he reached Maryse, his expression was incredulous. Clary gripped his hand tighter, feeling like she was being pulled in the wake of an angry battle ship.

"Someone stole from us?"

The head of the Institute turned to look at her adopted son, her eyes snapping. "Yes" she said, and Jace flinched at the fury in her voice. "Late last night the weapons cache and the library were both robbed."

"Weapons and books? Do we know what was taken?"

Maryse sighed. "All the _adamas_ weapons and seraph blades that were in the cache are gone. The steel weapons were left. The custodian is doing an inventory of the library now to see what was taken."

Adamas. That celestial metal which only shadowhunters could activate. Clary frowned, knowing that the runes set into the hafts of the seraph blades made them impossible for downworlders to touch.

"Why would downworlders take adamas weapons?" she asked out loud, and got a glare from Maryse.

"They wouldn't." Alec Lightwood came down the steps from the weapons cache, his expression matching his mothers. "There are no indications that downworlders entered the Institute by any means. None of the wards are broken, and there is no damage to the exterior doors or windows."

"That... but that means.."

"Shadowhunters" Maryse said, grimly.

* * *

Magnus yawned like a cat, stretching his body so far he almost arched out of his chair. Rubbing a hand over his face, he wrinkled his nose at the smudge of glitter and eyeliner that resulted and wiped the mess off onto his wrinkled shirt. All in all, he thought, he looked like a disaster. Still, his outfit was the least of his worries at the moment.

The photographs on his desk seemed to pull at him, accusatory and painful to look at. Three bodies, their original features and identities obliterated by trauma to the face and hands. The only thing obvious that connected them were their lineages – all were downworlders.

Visiting the morgue in the dead of night with Luke Garroway had been unpleasant. The chill of the freezers and the smell of blood still haunted Magnus even now. Despite a long acquaintance with death, the High Warlock of Brooklyn hated the trappings of it – funerals, morgues, crypts; anything which attempted to preserve or honor the dead gave him the horrors. Dead was dead, as far as he was concerned, and the bodies better off burned. One of the few shadowhunter traditions he agreed with.

The bodies had been mutilated after death, according to the ME reports. Two werewolves and a seelie, all butchered. Death had come from a single stab wound to the heart. Magnus didn't need a spell to confirm his suspicions – the x-rays of the wounds showed the characteristically curved path of a thick, heated blade. Cauterized instantly, the hearts were divided in two. Luke's expression had answered his reluctant question. The kills had been made with seraph blades.

With a sigh, he turned over the pictures as he heard a key in the door. Shuffling the documents away and dropping them in his desk drawer, he glanced in the mirror and made a disgusted noise. Dousing himself with magic to refresh his outfit and makeup, he sashayed into the living room with a flirtatious "welcome home" on his lips for his lover. The words died in his mouth as he saw Alec's expression, and a lead weight settled on his chest.

* * *

Dario Rivella was running late for his classes. As usual. He cursed himself as he dashed up the steps from the tube station, darting across a road and almost dropping his satchel as he dodged a car. A slightly comical sight, with the oversize trousers which trailed on the floor as he ran and the way that his gait seemed to be slightly... off. As he drew looks, he realised he'd forgotten to ward himself once again in his hurry to be out the door.

Flinging himself down the escalator into the southbound tube station on his left, he clutched at his hood to avoid showing the small horns peeking through his hair. Collapsing onto a bench, he took advantage of the empty station to apply an appearance ward, hiding the awkward bend of his goatish knees and the tips of his horns. Relaxing with a huff, he pulled out his binder and checked the times for the trains.

A pair of men entered the station. All in black, with hoods covering their heads and short, biker styled leather jackets, they could have been mistaken for rebel youngsters out on the town. Only the way they moved suggested anything else.

The young warlock didn't notice their arrival, too intent on getting in some last minute revision for his college exams. The two figures approached silently and by the time Dario looked up, it was far too late for him to do any more than scream as the smallest figure drove a gleaming seraph blade into his heart. Blood splashed across the tiles, coating the hand written study timetables and the library books in his bag. As the second figure pulled out a short adamas dagger and began working on his hands and face, blood pooled under the bench and flowed across the station floor.

 


	3. Discovery and passage

**Summary for the Chapter:**

> The discovery of a murdered warlock sets Magnus Bane on a dangerous path.

**Notes for the Chapter:**

> Ahhhh.... it's been forever since I updated this. Thanks to the lovely people who left kudos recently, you prompted me to continue working on it. I hope it's worth the wait!
> 
> Usual fanfiction caveats apply. The concepts and imagery for the Spiral Labyrinth are entirely my own, so I trust you won't hate on it too much!

“Dario Rivella, 18 years old. His foster mother sent him off to college four days ago, she reported him missing that evening.”

Luke crouched down to view the mess at a better angle. “He was a good kid – no record, no unusual incidents. Just a normal kid, doing classes. His mom said he liked to play computer games.”

With a sigh, Luke straightened and turned to Magnus. The expression on the usually cheerful warlock's face made him pause – a mixture of revulsion and fury seemed to be doing battle over his features. Fury appeared to be winning.

“Magnus...”

The warlock waved a hand and turned away. “I trust you'll take care of the mundanes?” he asked as he made his way back to the police line at the entrance to the alley.

“Of course, but Magnus...”

A portal tore itself into the wall near the police taking witness statements, glamoured by magic just as Magnus himself was. Without another word, Magnus was gone.

Luke sighed, then raised an eyebrow as Alec dropped from the building roof into the alley next to him, silent as a cat. “You're hiding from him?” he asked, and the tall shadowhunter shook his head.

“Not hiding. Working.”

Something in his expression gave him away, and Luke frowned. “The Clave are involved” he guessed, and Alec nodded. “Shadowhunter business, no downworlder involvement” he confirmed with a grimace.

Luke bristled, and Alec raised his hands quickly. “Not my rules. I'll share what I find out with both of you, when I know more. On the down-low though, OK?”

“Fine. Don't think we haven't noticed that these are nephilim kills” Luke warned. “I'm doing my best to keep the details quiet, but that won't last.”

Alec bent down and carefully inspected the corpse propped against the wall. “He died somewhere else, have you found that place yet?”

“The subway three blocks from here. Place is a bloodbath. They didn't even bother to clean up.”

“Then why move him at all” Alec wondered aloud, then cursed quietly. “Luke... his head.”

“I know” the detective growled, his eyes gleaming werewolf green for a moment. “His warlock mark is gone. Cut off, and taken away/”

“Trophies” Alec finished, his voice hard. “Luke, we're going to figure this out. I promise.”

* * *

 

“Warlocks, werewolves and seelies, oh my” Magnus muttered as he brushed cobwebs out of his hair and ignited a small sphere of magic in his hand, casting a faint glow around him. “Vampires bite, warlocks might, first star I see tonight.” He paused for a moment to get his bearings, and then began walking again, his path taking him downwards and to the east.

The glow illuminated the tunnel he was walking through, revealing a low ceiling and thick looking stone walls. Dust and cobwebs were prevalent, with only a few tracks here and there to indicate this path was used. Along the walls, every few yards a crystal was set, varied colours and hues pressed improbably pressed into the stone. Magnus occasionally touched them as he passed, even pausing to breathe on one. Sparkles of magic deep in the crystal indicated his ministrations were having an effect, and at each turn or corner one of the crystals in the distance would glow faintly. Even if someone managed to trick their way inside, it was impossible to navigate the Spiral Labyrinth without warlock magic.

After a few miles, his seemingly bizarre muttering was echoed by a male voice somewhere in the darkness.

“Unusual time for a visit, High Warlock? Don't you normally fly south for the winter?”

“You're thinking of sparrows” Magnus said, reproachfully. “Is the Gatekeeper awake?”

The owner of the male voice stepped into the dim pool of light, his expression welcoming despite the huge tusks that curled from his upper jaw. His eyes gleamed an unwholesome red, but were crinkled in pleasure at seeing Magnus. They briefly clasped arms for a moment, then began walking back the way they had come. The path seemed to shift around them, subtly different and taking a northerly direction, in defiance of logic and physics. Neither of them seemed surprised by this.

The crystals which had been guiding Magnus faded, replaced by runes on the walls. Magnus raised an eyebrow then chuckled. “Old Norse?” he asked, and the other warlock sighed. “I can't help it. The Labyrinth decided long ago that my guide would be my native language. It's fairly embarrassing.”

Magnus shrugged, watching the other warlock as he activated the runes and then following his lead.

“We got your message.” The walrus-tusked warlock handed Magnus a package of papers and photographs. “Tessa said be careful who you show it to. She also said you should come and visit properly when you have time.”

Magnus smiled sadly. “Time never seems to be on my side, Harkan. Or perhaps I worry about loosing too much of it here.”

“True. You have a mortal lover, I understand. It would be sad for you to miss years of his life by getting distracted by the Spiral. As much as we'd enjoy your company, of course.”

As Magnus nodded, the tunnel began to lighten naturally and widen, approaching a large enclave. The soft murmur of voices ceased as they entered the room, and three sets of eyes turned to them.

“Gatekeeper” Magnus said, his voice formal. He bowed slightly, suppressing a shudder at the sight of the thing that took up most of the space in the room.

The three sets of eyes remained fixed on him as the Gatekeeper slowly unfurled its tendrils, revealing a set of doors along the east wall. As it blinked slowly, the middle of the three heads opened its mouth and spoke in a low, male voice.

“You seek passage to the Swamp of the Dead. Are you willing to pay the price?”

Magnus straightened and dipped his hand into his pocket, producing a small, glistening frog. The tiny creature sat calmly on his hand, throat bobbing as it tasted the air.

The leftmost head glanced at Harkan, who was watching the frog hungrily. “You may leave. His passage is granted.”

Harkan nodded and rested his hand on Magnus's shoulder. “Be well” he said, before shuffling back out of the room.

“Pay the price, High Warlock, and pass through the northern gate” the rightmost head intoned.

Magnus held the small frog high, and a whip-like tendril snatched it off his hand. As the tiny green amphibian disappeared into the squirming mass of roots and vines that made up the body of the Gatekeeper, there was a bright flash from the northernmost door and the lock snapped open. The door seemed to fade, to be replaced by rolling smoke and a bone deep chill. A scent of dank earth and rotting meat filled the air, carried by the freezing draught from the doorway. The High Warlock of Brooklyn shuddered, despite himself.

“Before I go in there” Magnus said, his manner oddly subdued, “do you happen to know where the exit is? I'd hate to get stuck in that... place.”

The middle head rolled its eyes in an irritated gesture, but the right-hand head seemed to take pity on him. “Near the bottomless cavern, you'll find a copse of grave-trees. The exit is beneath them” it intoned. Magnus bowed again, then without further hesitation he strode through the doorway and disappeared into the smoke.


End file.
